bluebird-download.js

/*
* bluebird 顺序批量下载
*/

const Promise = require("bluebird");
const cmd = require('node-cmd');
const cmdRuner = Promise.promisify(cmd.get, { multiArgs: true, context: cmd });
let arr = [];
const makePromise = function(i) {
  return new Promise((resolve, reject) => {
    console.log(`开始下载第${i}个视频`);
    cmdRuner(`you-get https://cdn.xxxx.com/v/${i}.mp4`).then((res) => {
      console.log(`第${i}个视频下载完毕`);
      resolve(res);
    }).catch((e) => {
      reject(e);
    })
  })
}

for (let i = 1; i < 3; i++) {
  arr.push(i);
}

Promise.mapSeries(arr, (item, index) => makePromise(item)).then(res => {
  console.log('->', 'done');
}).catch((e) => {
  console.log('error->', e)
})